This paper addresses the relationship between mandatory and voluntary information. The introduction of IFRS in 2005 modified mandatory information requirements and influenced the content and level of the discretionary information disclosed by firms. This background allows us to test whether the complementary or substitution hypothesis dominates. A French firm data panel is used to empirically analyze the consequence of IFRS introduction. Referring to the 2003–2008 period gives a long-term perspective and allows us to identify discretionary communication policies by building a proprietary voluntary disclosure score. We find that voluntary disclosure policies experienced an upward swing with the introduction of IFRS, giving support to the complementary hypothesis. We also demonstrate a dynamic relationship between disclosure and the dispersion of analysts' earnings forecasts. The practical implication of the paper is to show that firms' discretionary communication policies follow both a long-term and a short-term component to meet analysts' demands for information. Our contribution is to refer to a long-term sample in one country where the environment and regulation context is homogenous. Our disclosure score index seems to be a good measure to outline that idiosyncratic communication policies are complex and strategic.